Three specific models will be employed to evaluate the effects of morphine on the nervous system. 1. 3H-1-lysine accumulation in motor, sensory, cerebellar, hippocampal, and neurosecretory neurons will be compared in male rats at various time intervals after amino acid injection in animals treated with morphine, morphine and naloxone, alone, or saline via indwelling cannulas in the awakened state. Since our previous results on amino acid accumulation into neurons 24 hours after morphine treatment differ from those of other workers, we will continue to observe the morphine effects at both the 2 and 24 hour intervals after treatment. 2. The effect of naloxone, p-chlorophenylalanine and 6-hydroxydopamine on the induction by morphine treatment of smooth endoplasmic whorls and synaptic changes in the arcuate nucleus will be investigated electron microscopically. 3. An attempt will be made to evaluate the quality of brain protein regionally by disc gel electrophoresis in morphine treated adults and neonates from mothers treated with morphine during pregnancy.